.periodic {
    width: 100%;
    height: 300px;
    background: #334D98;
}

@media only screen and (max-width: 1425px) {
    .periodic {
        height: inherit;
        background: inherit;
    }
}

.main-content {
    padding-top: 40px;
    padding-bottom: 80px;
}

.main-content p {
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}
.main-content h3 {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

.main-content h1 {
    text-align: center;
    margin-top: 10px;
    margin-bottom: 20px;
}

.main-list {
    display: flex;
    flex-wrap: wrap;
    grid-gap: 20px;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
    margin-top: 40px;
    justify-content: center;
}

.main-list li {
    max-width: 150px;
    transition: .25s;
}
.main-list li:hover {
    transform: scale(1.05);
}

.main-list li h2{
   font-size: 1.125rem;
   color: #fff;
}

.main-content .btn {
    margin-left: auto;
    margin-right: auto;
    margin-top: 40px;
    border-radius: 50%;
    padding: 20px;
    transition: .3s;
}
.main-content .btn:hover {
    color: #F6D10E;
    box-shadow: 0px 0px 0px 4px #fff, 0px 0px 0px 6px #334D98;
}

@media only screen and (max-width: 750px){

}